The present invention is directed to a concentrated glass and window liquid cleaning composition, more particularly to a concentrated glass and window liquid cleaning composition which has high solvent levels and low surfactant levels yet shows homogeneity in solution and excellent cleaning ability. A method for using such composition is also disclosed.
The compositions of the present invention and the methods of use relate to the specialized class of concentrated cleaning products which are designed to be used as is or diluted by the end user to a preferred strength for the particular job at hand. Such concentrated cleaning compositions can be applied from any type of hand-operated sprayer or from a bucket dilution, and more particularly can be applied from a hand-held sprayer such as is found in U.S. Pat. No. 5,152,461 and patent application Ser. No. 07/865,001, both of which are hereby incorporated by reference.
There has long been a desire to produce concentrated cleaners for consumer use. Concentrated cleaners provide high strength cleaning for difficult soils, economical solutions when diluted and minimize packaging and transportation costs. In some cleaning applications, such as heavy duty laundry applications, concentrated formulas based on high surfactant levels are known in the art and have been prepared successfully with the use of suitable surfactants and hydrotropes. Likewise, powder formulations with high concentrations are known in the art and are typically made through the use of agglomeration or similar technology.
Similarly, glass and window cleaners are known in the art such as that found in U.S. Pat. No. 4,863,629 which discloses glass and window cleaners having from 1% to 20% of a surfactant and from 1% to 20% of propylene glycol tert butyl ether. However, highly concentrated glass and window cleaners with low levels of surfactants and high levels of solvents which show homogeneity in solution and can be diluted by the end user to a preferred strength are not known in the art. This is due in part to the need in a consumer product of several characteristics such as dilutability, limited streaking, quick evaporation, good cleaning characteristics, stability and the ability to meet safety standards for household use.
Problems often occur when attempting to produce a glass and window cleaner in highly concentrated form such as the composition of the present invention. Solvents which evaporate quickly typically have low flash points and on increasing the concentration of these solvents, compositions with unacceptably low formula flash points are produced. Also, typically, solvents which exhibit high soil solvency tend to have lower evaporation rates, which results in products which are difficult for the consumer to use. Therefore, above certain solvent concentrations, it has been difficult to formulate a concentrated product which meets consumer acceptability. Further, streaking is often an inherent problem in glass and window cleaning compositions. Therefore, the use of builder salts or high levels of surfactants in order to increase the concentrations of the product or the cleaning ability of the products is discouraged as builder salts and surfactants can create or increase streaking.
One approach known in the art has been the use of solvent blends, combining higher and lower volatility solvents, to enhance evaporation and raise flash points. Solvent blends with both high evaporation rates and high flash points typically exhibit instabilities in product formulations containing surfactants and water. Further, high solvent glass and window cleaning systems typically suffer from problems of lack of homogeneity, thus requiring the consumer to extensively agitate the product prior to using in order to obtain an equal dispersion of materials.